The present invention relates to a wave shape generator for electronic musical instruments, and more particularly relates to improvement in a wave shape memory in which a certain wave shape stored in a wave shape memory is read out by periodical address signals in order to produce a wave shape signal to be used for generation of a corresponding musical tone.
In an electronic musical instrument, a wave shape generator having one or more wave shape memories is used for generation of musical tone wave shapes and envelope wave shapes. The wave shape generator outputs musical tone wave shapes upon receipt of frequency information from the associated frequency information memory.
In the case of the conventional wave shape generator of the above-described type, only the integer part of the accumulated value of the frequency information is utilized as the read-out address signal for the wave shape memory. This partial utilization of the given information naturally leads to low accuracy of read-out address signals with respect to the time axis and a large amount of quantization noise in the obtained musical tone wave.
In order to avoid the above-described disadvantages, it is necessary to increase the address shifting speed and to enlarge the data storing capacity of the memories.